Water hoses having extruded polyurethane resin or polyvinyl chloride resin helically coiled tubes with cross-sections having circular interior and exterior surfaces are commercially available. The tubes are coiled to enable the hoses, when stored, to have adjacent abutting or substantially abutting turns. In use, one end of such a hose is connected to a standard faucet and a user pulls on the other end of the hose, causing the adjacent abutting turns to become spaced from each other, resulting in partial uncoiling of the tube. Upon release by the user, the tube again becomes tightly coiled so that adjacent turns again abut or substantially abut. Hoses having such tubes are considered desirable because of the ease with which they are stored and the small amount of space they occupy during storage.
Such hoses having extruded polyvinyl chloride resin helically coiled tubes have greater flexure than hoses having extruded polyurethane resin coiled tubes with otherwise identical properties. The greater flexure of the polyvinyl chloride tubes enables the polyvinyl chloride tubes to be uncoiled more easily than the polyurethane resin tubes. In addition, tubes made of polyvinyl chloride resin are less expensive than tubes made of polyurethane resin. However, a disadvantage of helically coiled polyvinyl chloride resin tubes relative to hectically coiled polyurethane tubes is that the helix of a polyvinyl chloride resin tube must have a relatively small diameter to provide the tube with a sufficiently large flexural modulus to maintain the adjacent turns of the tube in an abutting relationship. (Flexural modulus is also referred to as flexural rigidity; it is a constant indicative of the ability of a structure to bend; flexural modulus is equal to the Young's modulus of the material in the structure times the moment of inertia of the structure; it is also equal to the square of the radius of gyration of a cross-section of the structure perpendicular to the plane in which the structure is being bent.) In fact, the commercially available hoses having polyvinyl chloride resin helically coiled tubes, when stored, have adjacent turns that frequently do not abut or even substantially abut so that such hoses cannot be stored in an optimum, minimum space condition.
To achieve abutment of adjacent turns during storage, the commercially available hoses with extruded polyurethane resin helically coiled tubes apparently must have circular inner diameters in the range of 0.0125 to 0.375 inch and circular outer diameters in the range of 0.245 to 0.5625 inch; in addition the windings of the helical coils apparently must have an inner diameter in the range of 0.5 to 2.5 inches and be made of polyurethane having a durometer hardness measurement in the range of 85 to 98 Shore A; see U.S. Pat. Nos. 5,964,412 and 6,209,800. However, such tubes are difficult to uncoil because they have such a large hardness measurement. In addition, these hoses, when stored, are somewhat long because the windings of the helical coil have a maximum inner diameter of 2.5 inches.
It is, accordingly, an object of the present invention to provide a new and improved hose including a coiled tube.
Another object of the invention is to provide a new and improved liquid dispensing hose including a coiled tube, wherein the hose is relatively easy to uncoil and which returns to a substantially recoiled condition, with adjacent turns in abutting or substantially abutting relationship.
An additional object of the invention is to provide a new and improved liquid dispensing hose including a coiled tube, wherein the hose is relatively easy to uncoil and has a relatively short length when stored.
A further object of the invention is to provide a new and improved water hose including a coiled tube having an exterior construction arranged to resist wear of the tube as the tube is pulled along the ground and which is stiffer than coiled tube hoses which are otherwise the same.